Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
  • C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
  • C08G12/40—Chemically modified polycondensates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/14—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
  • C04B40/0028—Aspects relating to the mixing step of the mortar preparation
  • C04B40/0039—Premixtures of ingredients
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/40—Surface-active agents, dispersants
  • C04B2103/408—Dispersants
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/72—Repairing or restoring existing buildings or building materials

Definitions

• the subject of the present invention is a formulation for the dispersion of hydraulic binder and especially gypsum containing compositions.
• Usual dispersants are static in their chemical structure over time in hydraulic systems. Their performance is controlled by monomer molar ratio that is fixed within a polymer molecule. A water reducing effect or dispersing effect is observed upon dispersant adsorption onto the hydraulic particle surface. As dispersant demand increases over time due to abrasion and hydration product formation, which creates more surface area, these conventional dispersants are unable to respond and workability is lost..
• Various types of organic compounds have been used to advantageously after certain properties of wet hydraulic binder compositions.
• One class of components which can collectively be called “superplasticizers” fluidify or plasticize wet binder compositions to obtain a more fluid mixture.
• a controlled fluidity is desired, such that the aggregate used in mortars and concretes does not segregate from the binder paste.
• superplasticizers may allow the cement composition to be prepared using a lower water: binder ratio in order to obtain a composition having a desired consistency which often leads to a hardened composition having a higher compressive strength development after setting.
• a good superplasticizer should not only fluidify the wet hydraulic binder composition to which it is added, but also maintain the level of fluidity over a desired period of time. This time should be long enough to keep the wet composition fluid, e. g. in a ready-mix truck while it is on its way to a job site. Another important aspect relates to the period for discharging the truck at the job site and the period needed for the cement composition for being worked in the desired final form. On the other side, the hydraulic mixture cannot remain fluid for a too long time, that means the set must not greatly be retarded, because this will slow down the work on the job and show negative influences on the characteristics of the final hardened products.
• superplasticizers are melamine sulfonate/formaldehyde condensation products, naphthalene sulfonate/formaldehyde condensation products and lignosulfonates, polysaccharides, hydroxycarboxylic acids and their salts and carbohydrates.
• fluidizing agents are multi-component products with copolymers based on oxyalkylenglykolalkenylethers and unsaturated dicarboxylic acid-derivatives as most important species.
• the European Patent EP 0 736 553 B1 discloses such copolymers comprising at least three sub-units and especially one unsaturated dicarboxylic acid derivative, one oxyalkylenglykolalkenylether and additionally one hydrophobic structural unit, such as ester units.
• the third structural unit can also be represented by polypropylenoxid- and polypropylenoxid-polyethylenoxid-derivatives, respectively.
• German published application DE 195 43 304 A1 discloses an additive for water containing mixtures for the construction field comprising a) a water-soluble sulfonic acid-, carboxylic- or sulfate group containing cellulose derivative, b) a sulfonic acid- and/or carboxylic acid containing vinyl-(co)-polymer and/or a condensation product based on aminoplast-builders or acryl containing compounds and formaldehyde.
• This additive shall show sufficient water retention ability and rheology-modifying properties. Therefore, this additive shall be suitable for construction chemical compositions containing cement, lime, gypsum, anhydrite and other hydraulic binder components.
• Copolymers based on unsaturated monocarboxylic or dicarboxylic acid derivatives, oxyalkylenglykolalkenylethers, vinylic polyalkylenglykol, polysiloxane or ester compounds used as additives for aqueous suspensions based on mineral or bituminous binders are described in US 6,777,517 B1 .
• the use of such additives results in a decrease in the water/binder ratio and leads to highly fluid building materials without segregation of individual constituents from the building material mixture.
• patents are useful as additives for aqueous suspensions of inorganic and organic solids and especially for suspensions that are based on mineral or bituminous binders such as cement, plaster of paris, lime, anhydrite or other building materials based on calcium sulfate.
• mineral or bituminous binders such as cement, plaster of paris, lime, anhydrite or other building materials based on calcium sulfate.
• copolymers of ethylenically unsaturated ethers that can be used as plasticizers for cement containing mixtures (EP 0 537 870 A1 ). These copolymers contain an ether co-monomer and as additional co-monomer an olefinic unsaturated mono-carboxylic acid or an ester or a salt thereof, or alternatively an olefinic unsaturated sulfuric acid. These copolymers show a very short ether side chain with 1 to 50 units. The short side chain causes a sufficient plasticizing effect of the copolymers in cement containing masses with a reduced slump loss of the construction chemicals mass itself.
• US 6,139,623 B1 discloses an emulsion admixture for use in hydraulic cement compositions formed by emulsifying an antifoaming agent, a surfactant and a copolymer having a carbon-containing backbone to which are attached groups that function as cement-anchoring members by forming ionic bonds and oxyalkylene groups.
• This admixture comprising an ethylene oxide/propylene oxide (EO/PO) type comb polymer and an antifoaming agent allows a predictable air control in hydraulic cement compositions such as concrete.
• cement composition refers to pastes, mortars, grouts such as oil well cementing grouts, and concrete compositions comprising a hydraulic cement binder.
• Typical antifoaming agents are phosphate ester, borate ester and polyoxyalkylene copolymers with defoaming properties.
• the surface active component is said to stabilize the emulsion mixture and is chosen from the group consisting of an esterified fatty acid ester of a carbohydrate, a C 2 to C 20 alcohol having polyoxyalkylene groups or a mixture thereof.
• US 2006/0281886 discloses a co-polymer comprising two monomer components with a component a) being an olefinic unsaturated monocarboxylic acid co-monomer or an ester or a salt thereof or an olefinic unsaturated sulfonic acid co-monomer or a salt thereof, and with component b) preferably represented by an ether compound.
• component a) being an olefinic unsaturated monocarboxylic acid co-monomer or an ester or a salt thereof or an olefinic unsaturated sulfonic acid co-monomer or a salt thereof
• component b) preferably represented by an ether compound.
• These two monomeric co-polymer can be preferably used as a superplasticizer in a hydraulic binder containing composition.
• the co-polymer can be used in combination with a defoaming component that is also an additional structural unit of the co-polymer.
• the defoaming component can be chemically attached to the co-polymer or being present in free form in a blend.
• dispersing agents such as polycarboxylate ethers (PCE)
• PCE polycarboxylate ethers
• the workability and preferably the rheological behavior of the construction chemicals composition are improved.
• PCE based dispersants causes a distinct air entrainment to the binder component that worsens the physical properties of the composition.
• Another negative aspect is the foam formation during the preparation of the binder system.
• defoamer components are used as additional additive to the dispersing agent.
• defoamers show a low solubility in aqueous formulations and cause an insufficient stability.
• the defoaming properties of the formulation decrease over time due to the resulting phase separation of the defoamer and the dispersant.
• US 2008/017078 teaches a liquid admixture composition for a calcium sulfate based binder system and a method of use.
• the disclosed admixture comprises an aqueous composition of a copolymeric dispersing component, an antifoaming agent component, a surfactant component and water.
• the components may be a blend or physically or chemically attached and result in a stable liquid system that can be used as dispersing agent for calcium sulfate compound containing construction chemicals composition.
• the admixture composition disclosed in this document and especially its application as dispersing agent represent a further improvement of this state of the art because the admixture with its contained aqueous composition induces a uniform plasticizing effect all the time and an improvement of the physical properties due to reduction of both water and air content in the wet construction chemicals gypsum mass. Furthermore, the admixture shows an improved storage stability and homogeneity.
• Gypsum mixtures for foaming, solid and fast drying gypsum products and a method of making a gypsum slurry by using modifiers and dispersants are disclosed by US 2009/0101045 , US 2006/0281837 , US 2006/0280899 , US 2006/0280898 , US 2006/0278135 , US 2006/0278134 , US 2006/0278130 , US 2006/0278127 , US 2005/0250888 , US 2005/0239924 and US 2006/0280970 .
• the dispersants mentioned in these documents represent polycarboxylate dispersants, the dispersant having two repeating units with an olefinic unsaturated mono-carboxylic acid repeating unit and a vinyl or allyl-group bound to a polyether by an ether linkage as second repeating unit.
• a formulation for extending workability to a hydraulic binder and preferably a calcium sulfate containing mixture and water comprising introducing into the mixture a combination of dispersing components.
• the subject formulation achieves a better workability and fluidibility of hydraulic setting compositions and establishes a low water/hydraulic binder value.
• the present invention relates to a formulation containing
• hydroaulic binder means cement and preferably Portland cement represented by CEM I, CEM II, CEM III, CEM IV and CEM V, white cement, quick lime and aluminate cement.
• latent hydraulic binder means at least one representative selected from the group fly ash, blast furnace slag, metakaoline, microsilica, trass compounds, alumosilicates, tuff, phomulithe, diatomaceous earth and oil shell.
• calcium sulfate compound means calcium sulfate in its anhydrous and hydrate forms, such as gypsum, anhydrite, calcium sulfate dihydrate and calcium sulfate hemi-hydrate.
• gypsum is also known as calcium sulfate, whereby calcium sulfate can be used in its various anhydrous and hydrate forms with or without crystal water.
• Natural gypsum is represented by calcium sulfate dihydrate and the natural crystal water free form of calcium sulfate is represented by the term "anhydrite”.
• anhydrite the natural crystal water free form of calcium sulfate.
• calcium sulfate is a typical by-product of technical processes characterized by the term “synthetic gypsum”.
• synthetic gypsum One example of such technical processes is the flue gas desulphurization.
• Synthetic gypsum may also be a by-product of phosphorous acid and hydrogen fluoride production methods for gaining hemi-hydrate forms (CaSO 4 1 ⁇ 2 H 2 O).
• Gypsum (CaSO 4 ⁇ 2H 2 O) may be calcinated by driving off the water of hydration. Products of the various calcinating procedures are alpha or beta hemi-hydrate.
• Beta calcium sulfate hemi-hydrate results from a rapid heating in open units by a rapid evaporation of water and by forming cavities.
• Alpha hemi-hydrate is produced by a de-watering of gypsum in closed autoclaves. The crystal form in this case is dense and therefore, this binder needs less amounts of water than beta hemi-hydrate.
• gypsum hemi-hydrate re-hydrates with water to dihydrate crystals.
• the hydration of gypsum needs some minutes to hours indicating a clearly shortened workability period in contrast to cements that hydrate in periods over hours or days.
• Calcium sulfate hemi-hydrate can produce at least two crystal forms, whereby ⁇ -calcined gypsum is usually de-watered (de-hydrated) in closed autoclaves.
• ⁇ -calcined gypsum may be selected due to its availability under economical aspects. However, these advantages may be reversed because ⁇ -calcined gypsum needs higher water amounts for workability and for making slurries of a given fluidity. Hardened or dried gypsum tends to a certain weakening based on the remained water in its crystal matrix. Therefore, products thereof show less strength than gypsum products that have been made with smaller amounts of water.
• the workability of gypsum, but also of other hydraulic binders, can be improved under hydraulic aspects by adding dispersants.
• the formulation according to this invention represents a suitable dispersant because of the dispersing properties of its component.
• Component a) of the formulation according to the invention has dispersing properties and is selected from the group consisting of a compound at least containing a branched comb polymer having polyether side chains, a naphthalene sulphonate-formaldehyde condensate ("BNS”), and a melamine sulphonate-formaldehyde condensate (“MSF”), Formulations which contain a branched comb polymer having polyether side chains as the component a) with dispersant action have been found extremely effective.
• BNS naphthalene sulphonate-formaldehyde condensate
• MSF melamine sulphonate-formaldehyde condensate
• the component a) is a polycarboxylate ether a 1 ), a polycarboxylate ester a 2 ), an uncharged copolymer a 3 ) or a mixture thereof.
• polycarboxylate ester a 2 are preferred that show anti-foaming and surface active activities.
• Such polyether-containing copolymers which in the sense of the present invention are suitable as component a 1 ), have been previously described in WO 2006/133933 A2 .
• the present invention comprises a formulation wherein the copolymer a 1 ) contains the comonomer component 1) in proportions of 30 to 99 mol.% and the comonomer component 2) in proportions of 70 to 1 mol.%.
• a copolymer a 1 ) which contains the comonomer component 1) in proportions of 40 to 90 mol.% and the comonomer component 2) in proportions of 60 to 10 mol.% has been found particularly advantageous in this connection.
• the comonomer component 1) derives from the group acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, allylsulphonic acid, vinylsulphonic acid and suitable salts thereof and alkyl or hydroxyalkyl esters thereof.
• the copolymer a 1 can have additional structural groups in copolymerized form, which is also taken into account by the present invention.
• the additional structural groups may be styrenes, acrylamides and/or hydrophobic compounds, ester structural units, polypropylene oxide and polypropylene oxide/polyethylene oxide units being particularly preferred.
• the copolymer a 1 ) should contain the said additional structural groups in proportions up to 5 mol.%, preferably from 0.05 to 3.0 mol.% and in particular from 0.1 to 1.0 mol.%.
• this ester a 2 is a polymer which can be prepared by polymerization of a monomer mixture (I) containing, as the main component, a representative of the carboxylic acid monomer type.
• a monomer mixture (I) containing, as the main component, a representative of the carboxylic acid monomer type.
• An important aspect of component a 2 ) according to the present invention has to be seen in the anti-foaming and/or defoaming and/or surface active properties of such polycarboxylate ester types. This is why the formulation according to the present invention also comprises a combination of an antifoaming/surface active agent with dispersing properties as component a) and the polycondensate component b).
• the monomer mixture (I) contains an (alkoxy)polyalkylene glycol mono(meth)acrylate monomer (a) of the general formula (II) in which R 1 represents a hydrogen atom or a CH 3 group, R 2 O represents one representative or a mixture of at least two oxyalkylene groups having 2 to 4 carbon atoms, R 3 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and m represents a number between 1 and 250 and represents the average number of moles of the oxyalkylene group added, additionally, as monomer (b), a (meth)acrylic acid of the general formula (III), in which R 4 represents a hydrogen atom or a CH 3 group and M 1 represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group, and optionally a monomer (c) which is copolymerized with the monomers (a) and (b).
• R 1 represents a hydrogen atom
• the monomer (a) can be present in an amount of from 5 to 98 wt.%, the monomer (b) in a proportion of from 2 to 95 wt.% and the monomer (c) in a proportion up to 50 wt.% in the monomer mixture (I), wherein the respective proportions of the monomers (a), (b) and (c) add up to 100 wt.%.
• the formulation according to the invention should contain at least one representative of the esters of an aliphatic alcohol with 1 to 20 carbon atoms with an unsaturated carboxylic acid.
• unsaturated carboxylic acid in particular maleic acid, fumaric acid, citraconic acid (meth)acrylic acid or monovalent metal salts, divalent metal salts, ammonium salts or organic amine salts thereof are especially suitable.
• Monoesters or diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid or citraconic acid with aliphatic C 1 -C 20 alcohols, C 2 -C 4 glycols or with (alkoxy)polyalkylene glycols are preferred representatives of monomer (c) according to the present invention.
• the component a 2 can be a copolymer which is made up of at least one of the following monomers:
• components B) and C) are simultaneously represented in the copolymer a 2 ) of the claimed formulation.
• the ethylenically unsaturated monomer of the component A) can be at least one anhydride or imide and/or at least one maleic anhydride or maleimide.
• the ethylenically unsaturated monomer of the component A) can however also include an acrylate ester with an ester functionality which contains the hydrolysable residue. In this case, it should be regarded as preferred if the ester functionality is at least one hydroxypropyl or hydroxyethyl radical.
• the copolymer a 2 ) can however comprise more than one ethylenically unsaturated monomer with a hydrolysable radical.
• the ethylenically unsaturated monomer of the component A) as a residue has at least more than one representative of the ethylenically unsaturated monomers, at least one representative of a hydrolysable radical or a mixture of both.
• the hydrolysable radical should have at least one C 2 -C 20 alcohol functionality.
• the present invention also includes the possibility that the hydrolysable residue is at least one C 1 -C 20 alkyl ester, one C 1 -C 20 aminoalkyl ester, one C 2 -C 20 alcohol, one C 2 -C 20 amino alcohol or one amide.
• the present invention further comprises that at least one ethylenically unsaturated monomer of the component B) or C) has a C 2 -C 8 alkyl ether group.
• the ethylenically unsaturated monomer can have a vinyl, allyl or (methyl)allyl ether residue or else be derived from an unsaturated C 2 -C 8 alcohol.
• at least vinyl alcohol, (meth)allyl alcohol, isoprenol or methylbutenol are especially preferred possibilities as representatives.
• the ethylenically unsaturated monomer side groups of the component B) or C) can however also contain at least one C 4 oxyalkylene unit.
• At least one ethylenically unsaturated monomer of the components B) or C) can have a C 2 -C 8 carboxylate ester, which in particular is hydrolysable.
• the present invention includes a modification wherein the oxyalkyl side groups have at least one ethylene oxide, one propylene oxide, one polyethylene oxide, one polypropylene oxide or mixtures thereof.
• the copolymer a 2 ) in the component C) can have at least one nonionic ("uncharged") and/or one non-hydrolysable monomer residue or mixtures thereof.
• the present invention also includes a third modification of the comb polymer a), which then is a nonionic (uncharged) copolymer a 3 ).
• R 1 and R 2 mutually independently mean at least one C 2 -C 8 alkyl
• R 3 comprises (CH 2 ) c , where c is a whole number between 2 and 5 and where mixtures of the representatives of R 3 in the same polymer molecule are possible
• R 5 means at least one representative selected from the series H, a linear or branched, saturated or unsaturated C 1 -C 20 aliphatic hydrocarbon residue, a C 5 -C 8 cycloaliphatic hydrocarbon residue or a substituted or unsubstituted C 6 -C 14 aryl residue
• nonionic copolymer a 3 can alternatively also be a representative of the general formula (V), wherein X stands for a hydrolysable residue and R for H or CH 3 , and G, p, R 1 , R 2 , R 3 , R 5 , m, n, w, y, z and (y + z) have the meanings stated under the formula (IV).
• the hydrolysable residue can be at least one representative of the series alkyl ester, aminoalkyl ester, hydroxyalkyl ester, aminohydroxyalkyl ester or amide.
• the present invention specifies at least one representative of the general formula (VI) wherein R 4 means at least one C 1 -C 20 alkyl or C 2 -C 20 hydroxyalkyl radical and the radicals G, p, R, R 1 , R 2 , R 3 , c, R 4 , R 5 and m, n, w, y, z and (y + z) have the meanings stated under the formulae (IV) and (V).
• the molar ratio of w to the sum (y + z) is 1 : 1 to 20 : 1 and preferably 2 : 1 to 12 :1.
• the representatives of the third modification of the copolymer a 3 ) corresponding to formula (VI) should in particular be a nonionic polyether-polyester copolymer.
• the present invention specifies that the formulation contain the component a) in proportions from 5 to 95% by weight, preferably of 10 to 60% by weight and particularly preferably of 15 to 40% by weight, based in each case on the total formulation.
• Sulphonic acid group containing s-triazines or naphthalene-formaldehyde condensates are broadly disclosed by prior art documents and frequently used as water reducing agents or plasticizers for cement based systems such as concrete.
• BNS ⁇ -naphthalene-sulphonate-formaldehyde condensates
• NFS naphthalene-formaldehyde sulphonates
• BNS or NFS is suitable for making cement particles with high dispersion, low foaming and high range water reducing and thereof it is possible to save the hydraulic binder such as cements or calcium sulphite based binders to improve the cement mobility and workability.
• BNS is a high range admixture for concrete, cast-in-place, prefabricating, pump and curing and BNS has a good adaptability to cements and other hydraulic binders and is not corrosive to reinforcing bar and non poisonous and pollution-free. Therefore it has been broadly applied to the construction industry such as highways, bridges, tunnels, industrial buildings, prestressing force components and high range concretes.
• condensates suitable as plasticizer or dispersants are prepared by the reaction of aromatic sulphonic acids like naphthalene sulphonic acid with formaldehyde under ambient pressure and under temperatures up to 100 °C.
• BNS The preparation and use of BNS is well known state of the art and disclosed for example in EP 0 214 412 A1 and DE-PS 2 007 603 .
• the effect and properties of BNS can be modified by changing the molar ratio between formaldehyde and the naphthalene component that usually is from 0.7 up to 3.5.
• the ratio between formaldehyde and the sulphonated naphthalene component preferably is from 0.8 to 3.5 to 1.
• BNS condensates are added to the hydraulic binder containing composition in amounts from 0.01 up to 6.0 wt.%.
• Melamine-sulphonate-formaldehyde-condensates are broadly used as flow improving agents in the processing of hydraulic binder containing compositions such as dry mortar mixtures, pourable mortars and other cement bonded construction materials.
• Melamine is used in this connection as representative of the s-triazine which is why these improving agents are known as MFS resins. They cause as well as the already mentioned BNS representatives a strong liquefying effect of the construction chemicals mixture without any undesired side effects occurring in the processing or in the functional properties of the hardened building material.
• MFS resins The liquefying effect of MFS products is achieved without lowering the surface tension of the water and binder system which usually is the case for the example with BNS products or flow improving agents with a surfactant-like polymers structure.
• the advantage of MFS resins is presumed to be due to the fact that no air avoids are introduced in to mortar during remixing process and the mortar density and strengths are not adversely effected after hardening.
• MFS resins provide the fresh mortar mixture with a good cohesive strength so that even when the flow properties are extreme separation phenomena within the construction composition do not occur. This phenomenon, also called as "segregation", is feared especially in the production of self-flowing smoothing compositions which especially is the case with self-leveling screeds since its leads to a non-uniform layer structure of the screed due to floating of the fine material and sedimentation of the coarse grain.
• sulfanilic acid containing condensation products based on amino-s-triazines that show at least two amino groups are prepared by using formaldehyde.
• the sulfanilic acid is used in amounts of from 1.0 to 1.6 mol per mol amino-s-triazine and neutralized in aqueous solution with an alkaline metal hydroxide or in earth alkaline metal hydroxide.
• the formaldehyde is added in amounts of from 3.0 to 4.0 mol per mol amino-s-triazine at a pH value between 5.0 to 7.0 and at temperatures between 50 and 90 °C.
• the final viscosity of the solution shall be between 10 and 60 cSt at 80 °C.
• DE 195 38 821 A1 discloses a condensate based on an amino-s-triazine with at least two amino groups and formaldehyde and a high content of sulphonic acid groups and a low content of formate.
• Such products can be prepared according to this document by reacting the amino-s-triazine, formaldehyde and a sulphite at a molar ratio of 1 : 3.0 : 6.0: 1.51 : 2.0 in an aqueous solution and at a temperature between 60 and 90 °C and a pH value between 9.0 and 13.0 until the sulphite is no longer present.
• the condensation process is conducted at a pH value between 3.0 and 6.5 and at temperatures between 60 and 80 °C until the condensation product at 80 °C shows a viscosity between 5 and 50 mm 2 /s.
• the condensation product is to be brought to a pH value between 7.5 and 12.0 or treated thermally by a pH ⁇ 10.0 and a temperature between 60 and 100 °C.
• the BNS and/or MFS dispersant is used in amounts of from 0.01 to 10 wt.% and preferably 0.1 to 5 wt.%, related to the hydraulic binder component.
• the molar ratio of the sulphonic group and related to the melamine component is of from 1.0 to 2.0 and the molar ratio of the formaldehyde related to the melamine component is from 2.5 to 5.0.
• the molar ratio melamine to sulphonic acid to formaldehyde is 1 : 1.1 : 1.5 : 3.3 : 3.6.
• the molar ratio of formaldehyde to naphthalene sulphonic acid is from 1.3 to 1 : 3 to 1.
• admixtures in the form of dispersants are added to aqueous slurries or pulverulent inorganic or organic substances, such as clays, silicate powder, chalk, carbon black, crushed rock and hydraulic binders, for improving their processability, i.e. kneadability, spreadability, sprayability, pumpability or flowability.
• Such admixtures are capable of preventing the formation of solid agglomerates and of dispersing the particles already present and those newly formed by hydration and in this way improving the processability. This effect is utilized in particular in a targeted manner in the preparation of construction material mixtures which contain hydraulic binders, such as cement, lime, gypsum, hemihydrate or anhydrite.
• admixtures are used which are generally referred to as water-reducing agents or plasticizers.
• water-reducing agents or plasticizers.
• plasticizers In practice, in particular polycondensates and copolymers are used as such agents.
• WO 2006/042709 describes polycondensates based on an aromatic or heteroaromatic compound (A) having 5 to 10 C atoms or heteroatoms, having at least one oxyethylene or oxypropylene radical, and an aldehyde (C) selected from the group consisting of formaldehyde, glyoxylic acid and benzaldehyde or mixtures thereof, which result in an improved plasticizing effect of inorganic binder suspensions compared with the conventionally used polycondensates and maintain this effect over a longer period ("slump retention").
• these may also be phosphated polycondensates.
• the phosphated monomers used are, however, relatively expensive since they have to be separately prepared and purified.
• the polycondensate contains a further structural unit (X) which is represented by the following formula
• R 6 and R 6 in structural unit (X), independently of one another, are preferably represented by H, COOM c and/or methyl.
• the molar ratio of the structural units (VII), (VIII), (IX) and (X) of the phosphated polycondensate according to the invention can be varied within wide ranges. This has proved to be expedient if the molar ratio of the structural units [(VII) + (VIII) + (IX)]:(X) is 1:0.8 to 3, preferably 1:0.9 to 2 and particularly preferably 1:0.95 to 1.2.
• the molar ratio of the structural units (VII):[(VIII) + (IX)] in component b) is usually 1:15 to 15:1, preferably 1:10 to 10:1 and more preferably 1:5 to 3:1.
• the molar ratio of the structural units (VIII):(IX) is adjusted to 1:0.005 to 1:10, preferrably 1:0.01 to 1:1, in particular 1:0.01 to 1:0.2 and more preferably 1:0.01 to 1:0.1.
• the groups A and D in the structural units (VII), (VIII) and (IX) of the polycondensate are generally represented by phenyl, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, naphthyl, 2-hydroxynaphthyl, 4-hydroxynaphthyl, 2-methoxynaphthyl, 4-methoxynaphthyl, preferably phenyl, it being possible for A and D to be chosen independently of one another and also in each case to consist of a mixture of said compounds.
• the groups B and E, independently of one another, are preferably represented by O.
• R 1 R 2 , R 3 and R 4 can be chosen independently of one another and are preferably represented by H, methyl, ethyl or phenyl, particularly preferably by H or methyl and especially preferably by H.
• a in structural unit (VII) is preferably represented by an integer from 5 to 280, in particular 10 to 160 and particularly preferably 12 to 120 and b in structural units (VIII) and (IX) by an integer from 0 to 10, preferably 1 to 7 and particularly preferably 1 to 5.
• the respective radicals, the length of which is defined by a and b, respectively, may consist here of uniform building blocks, but a mixture of different building blocks may also be expedient.
• the radicals of the structural units (VII) or (VIII) and (IX), independently of one another may each have the same chain length, a and b each being represented by a number. As a rule, however, it will be expedient if mixtures having different chain lengths are present in each case so that the radicals of the structural units in the polycondensate have different numerical values for a and independently for b.
• the phosphated polycondensate according to the present invention has a weight average molecular weight of 4000 g/mol to 150 000 g/mol, preferably 10 000 to 100 000 g/mol and particularly preferably 20 000 to 75 000 g/mol.
• the phosphated polycondensate according to the invention is present in the claimed formulation as aqueous solution which contains 2 to 90% by weight of water and 98 to 10% by weight of dissolved dry matter, preferably 40 to 80% by weight of water and 60 to 20% by weight of dissolved dry matter, and more preferably 45 to 75% by weight of water and 55 to 25% by weight of dissolved dry matter.
• the dry matter then substantially comprises the anhydrous phosphated polycondensate, where further components, such as antifoams and other auxiliaries, can advantageously also be present.
• the polycondensate b) is present in the formulation in proportions of 5 to 100% by weight, preferably of 10 to 60% by weight and particularly preferably of 15 to 40% by weight, based in each case on the total formulation.
• the invention furthermore envisages a sodium, potassium, ammonium and/or calcium salt and preferably a sodium and calcium salt, of the phosphated polycondensate.
• the present invention also relates to a process for the preparation of a phosphated polycondensate, it being regarded as essential that the polycondensation and the phosphation be carried out in a reaction mixture.
• This is to be understood as meaning that the phosphated component formed in the reaction solution needs neither be purified nor isolated.
• the phosphation can be carried out before, during or after the polycondensation. It is to be regarded as being preferred here to carry out both the phosphation and the polycondensation in the same reaction vessel.
• reaction mixture with regard to the polycondensate component b) contains at least
• the monomers (Ia), (IIa), (IIIa) and (IVa) and, in the polycondensate, the structural unit (IIa) are preferably represented by the following general formulae:
• the present invention provides different variants of the reaction procedure.
• One possibility consists in first reacting the monomer (IIIa) with a phosphating agent and subjecting the monomer (IIa) thus obtained to polycondensation with the monomers (Ia), (IIIa) and (IVa).
• the monomer (IIIa) may originate here from an incomplete reaction during the phosphation reaction or can be deliberately added to the reaction mixture after the phosphation reaction.
• the monomers (Ia), (IIIa) and (IVa) it is also possible to subject the monomers (Ia), (IIIa) and (IVa) to a polycondensation and then to react the polycondensate obtained with a phosphating agent.
• the monomers (Ia), (IIIa) and (IVa) and the phosphating agent are reacted simultaneously.
• polyphosphoric acid and/or phosphorous pentoxide have proved suitable here as phosphating agents.
• the polycondensation is carried out in the presence of an acidic catalyst, this preferably being sulphuric acid, methanesulphonic acid, para-toluenesulphonic acid or mixtures thereof.
• an acidic catalyst this preferably being sulphuric acid, methanesulphonic acid, para-toluenesulphonic acid or mixtures thereof.
• the polycondensation and the phosphation are advantageously carried out at a temperature between 20 and 140°C and a pressure between 1 and 10 bar.
• a temperature range between 80 and 110°C has proved to be expedient.
• the duration of the reaction may be between 0.1 and 24 hours, depending on temperature, the chemical nature of the monomers used and the desired degree of crosslinking. Once the desired degree of crosslinking has been reached, which can also be determined, for example, by measurement of the viscosity of the reaction mixture, the reaction mixture is cooled.
• the reaction mixture is subjected to a thermal aftertreatment at a pH between 8 and 13 and a temperature between 60 and 130°C after the end of the condensation and phosphation reaction.
• a thermal aftertreatment which advantageously lasts for between 5 minutes and 5 hours, it is possible substantially to reduce the aldehyde content, in particular the formaldehyde content, in the reaction solution.
• the present invention envisages subjecting the reaction mixture to a vacuum aftertreatment at pressures between 10 and 900 mbar after the end of the condensation and phosphation reaction, for reducing the aldehyde content.
• a vacuum aftertreatment at pressures between 10 and 900 mbar after the end of the condensation and phosphation reaction, for reducing the aldehyde content.
• other methods known to the person skilled in the art for reducing the formaldehyde content may also be used.
• An example is the addition of small amounts of sodium bisulphite, ethylene urea and/or polyethylenimine.
• the phosphated polycondensates obtained by these processes can be used directly as component b).
• Sodium hydroxide, potassium hydroxide, ammonium hydroxide or calcium hydroxide has proved to be particularly expedient here, it being regarded as being preferred to neutralize the reaction mixture.
• other alkali metal and alkaline earth metal salts and salts of organic amine are suitable as salts of the phosphated polycondensates.
• the present invention also provides the preparation of mixed salts of the phosphated polycondensates.
• These can expediently be prepared by reacting the polycondensates with at least two basic compounds.
• salts of the polycondensates according to the invention with which the duration of the processability of aqueous suspensions of inorganic binders and in particular of concrete can be influenced. While a reduction in the processability over time is observable in the case of the sodium salt, a complete reversal of this behavior takes place in the case of the calcium salt of the identical polymer, a smaller water reduction (smaller slump) occurring at the beginning and increasing with time.
• the corresponding phosphated polycondensates which consist of sodium and calcium salts, are prepared by reaction with a mixture of basic calcium and sodium compounds, in particular calcium hydroxide and sodium hydroxide.
• the catalyst used can also be separated off. This can expediently be effected via the salt formed during the neutralization. If sulphuric acid is used as a catalyst and the reaction solution is treated with calcium hydroxide, the calcium sulphate formed can be separated off, for example, in a simple manner by filtration.
• the phosphated polycondensate can be separated from the aqueous salt solution by phase separation and can be isolated. The phosphated polycondensate can then be taken up in the desired amount of water.
• the claimed formulation contains additionally to the components a) and b) at least one antifoaming agent c) and/or a component d) having a surface-active effect, the components c) and d) being structurally different from one another.
• said antifoaming agent c) comprises tri-alkylphosphate and more preferably triiso-butylphosphate, a polyoxypropylen copolymer and a glycerol/alcohol acetate.
• the invention additionally comprises an admixture wherein said antifoaming agent c) comprises a mixtures of a tri-alkylphosphate and a polyoxypropylene copolymer.
• the second optional component of the formulation namely the surfactant, is preferably selected from the group consisting of a ethylene oxide/propylene oxide (EO/PO) block copolymer, a styrene/maleic acid copolymer, a fatty alcohol alkoxylate, an alcohol ethoxylate R 10 -(EO)-H with R 10 being an aliphatic hydrocarbon group having from 1 to 25 carbon atoms, acetylenic diols, monoalkylpolyalkylenes, ethoxylated nonylphenols, alkylsulfates, alkylethersulfats, alkylethersulfonates, alkyl ether carboxylates.
• EO/PO ethylene oxide/propylene oxide
• More preferably surfactant component d) comprises an alcohol having a polyalkylene group consisting of a carbon chain length of 2 to 20 carbon atoms, with a specific carbon chain length of C 3 -C 12 .
• the formulation according to the invention comprises an aqueous composition that contains the antifoaming agent component c) in free form or attached to the dispersing components a), and/or b).
• the antifoaming agent is attached to the dispersing components it can be physically or chemically attached, and the chemically attached in this case in polymerized and/or grafted form being preferred.
• the antifoaming agent c) also can be considered as a third comonomer of the copolymeric dispersing components a 1 ), a 2 ), a 3 ).
• the antifoaming agent c) is a blend component of the formulation.
• antifoaming agent component c) is either physically and/or chemically attached to the dispersing components a 1 ), a 2 ) and/or a 3 ) and/or it is a free form component and therefore constituent of a blend.
• the antifoaming component c) is present in amounts of 0.01 to 10% by weight and/or the surface-active component d) is present in amounts of 0.01 to 10% by weight, based in each case on the total weight of the formulation.
• the antifoaming formulation according to any of Claims 52 to 61 characterized in that the antifoam c) and/or the surface-active component d), independently of one another, are present in each case in an amount of 0.01 to 5% by weight, based in each case on the total weight of the formulation.
• the present invention additionally comprises an embodiment whereby the formulation in addition to the components a) and b) and optionally c) and/or d), contains at least one further compound e) selected from the group consisting of a polymer having a low charge, a neutral polymer or polyvinyl alcohol.
• This component e) and particularly its specific role in systems containing calcium sulfate as hydraulic binder has been teached in the unpublished provisional European Patent application EP 08171022.0 .
• the component e) plays a major role in gypsum composition with certain clay contents.
• a formulation based on a branched comb polymer with ethylene oxide (EO) units in the side-chains for the dispersion of clay-containing gypsum mixtures are capable of masking clay minerals such as are in particular contained in natural gypsum to a sufficient extent that the surfaces thereof are no longer available for the adsorption of dispersants. They have no adverse effect on the fluidization and consistency of the wet and unhardened gypsum mixture and they are stable to the temperatures used in the drying of the gypsum products, so that no odour problems arise.
• a copolymer component a 2 is to prefer that is based on a hydrolysable monomer A having an active binding site for at least one component of the clay-containing gypsum mixture.
• the surface of the clay particles can be more effectively coated through the bunching of flexible EO side-chains on a polymer backbone or the clay particles can themselves be better flocculated overall. Because of the lower charge density, the component e) can adsorb mainly on the clay and not on the binder such as gypsum hemihydrate.
• the side-chains of the "sacrificial substance" must include EO units; however, the side-chains can also in addition have polyethylene oxide (PO) units.
• PO polyethylene oxide
• the main substance contained in the formulation according to the invention the comb polymer with dispersant properties; this can contain either EO or PO units or both in its side-chains.
• the mixed modifications can also each be implemented in at least one, that is the same, side-chain.
• the component e) optionally contained in the formulation according to the invention as a sacrificial substance to some extent differs only insignificantly from the dispersants a) commonly used in clay-containing gypsums, since it also consists inter alia of polycarboxylate ethers.
• the difference consists however in the charge state, since only representatives with low or neutral charge are possible as the sacrificial substance.
• the manufacture of gypsum products in particular can also be effected with the aid of dispersants which inter alia consist of copolymer mixtures wherein the low-charge or neutral polymer fractions predominantly mask the clay minerals and thus enable the remaining dispersant content to exert its actual fluidizing agent action.
• the advantageous action of the formulation according to the present invention and mainly based on component e) is displayed in essentially all clay-containing gypsum mixtures.
• the positive action is especially pronounced in gypsum systems which contain at least one representative of the series calcium sulphate, calcium sulphate semihydrate or calcium sulphate hemihydrate, anhydrite and gypsum.
• the clay fraction in the gypsum mixture should preferably be swellable and in particular water-swellable and derive from the series of the smectites, montmorillonites, bentonites, vermiculites, hectorites or from the series of the kaolins, feldspars and micas such as for example illite and mixtures thereof.
• the present invention recommends clay contents in the gypsum mixtures of ⁇ 10 wt.%, preferably ⁇ 6 wt.%, preferably ⁇ 4 wt.% and especially preferably between 0.5 and 3 wt.%, each based on the gypsum component.
• proportions from 0.01 to 0.40 wt.%, preferably from 0.02 to 0.30 wt.%, preferably from 0.03 to 0.15 wt.% and especially preferably from 0.5 to 0.10 wt.%, each again based on the gypsum component, are recommended.
• the formulation contains the component e) in amounts of 1 to 50% by weight, preferably of 5 to 40% by weight and particularly preferably in amounts of 10 to 30% by weight, based in each case on the total weight of the formulation.
• the polymer component e which reacts with the clay particles in the gypsum mixture, is of particular significance.
• this should be branched, the side-chain preferably consisting of a polyether.
• Polycarboxylate ethers and/or polycarboxylate esters, preferably with EO side-chains and with a carboxylate content up to 83 mol.%, and preferably up to 75 mol.% are to be regarded as especially preferred in this connection.
• component a) of the formulation should advantageously include at least one polycarboxylate derivative (ether, ester); in particular if this has a low charge content, it cannot on account of its specific properties adsorb for example onto gypsum to the necessary extent. For this reason, the generally known dispersant action of polycarboxylate ethers and esters in particular does not occur to the necessary extent in this case. Hence the content of the charge-bearing component is important for the dispersant action of such representatives.
• ether, ester polycarboxylate derivative
• copolymer components a 1 ), a 2 ) and a 3 ) and, to some extent, depending on its chemical character, also component e) can compete with one another as regards the dispersant action, it is advantageous overall to select the respective contents in the formulation according to the invention such that the copolymer component a) can exhibit its dispersant action to the maximum and the component e) because of its charge properties has as little dispersant action as possible, but instead is maximally adsorbed on the clay particles.
• a low-charge polymer with a polyether side-chain is used as component e), then this should be made up of at least one monomer selected from the series polyether monoacrylate, polyether monomethacrylate, polyether monoallyl ether, polyether monomaleate, monovinylated polyether or mixtures thereof.
• this can be an alkylene oxide polymer with a molecular weight from 500 to 10 000, preferably from 750 to 7500 and in particular from 1000 to 5000.
• alkylene oxide polymers those based on an ethylene oxide, propylene oxide, butylene oxide or mixtures thereof may be mentioned.
• Low-charge polymers which are built up of at least one monomer selected from the series polypropylene glycol acrylates, polypropylene glycol methacrylates, polyethylene glycol acrylates, polyethylene glycol methacrylates, polypropylene glycol monovinyl ethers, polythylene glycol monovinyl ethers, alkoxy or aryloxypolyethylene glycol acrylates, alkoxy or aryloxypolyethylene glycol methacrylates, alkoxy or aryloxy-polyethylene glycol monovinyl ethers, acrylates, methacrylates and monovinyl ethers of an oxyethylene and oxypropylene block or randomized copolymer, polypropylene glycol allyl ether, polyethylene glycol allyl ether, polyethylene glycol monomaleate, polypropylene glycol monomaleate and any mixtures thereof have been found especially suitable.
• the polymer e) having a low charge carries a carboxylic acid group, preferably selected from the series consisting of acrylic acid, methacryl acid, maleic acid, fumaric acid, itaconic acid or anhydrides thereof.
• the low-charge polymer can also bear a carboxylic acid and/or sulphonic acid groups.
• the carboxylic acid group is preferably at least one representative of the series acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid or anhydrides thereof.
• AMPS 2-Acrylamido-2-methylpropanesulphonic acid
• vinylsulphonic acid vinylsulphonic acid
• allyl ether sulphonic acid 2-sulphoethylmethacrylic acid
• styrenesulphonic acid methallyl-sulphonic acid
• sodium, potassium and ammonium salts and any mixtures thereof are preferred representatives of compounds which make sulphonic acid groups available.
• AMPS and vinylsulphonic acid are to be regarded as especially preferable.
• neutral polymers as component e), these should be made up of neutral monomer building blocks, which are in particular selected from the series acrylic acid alkyl esters and methacrylic acid alkyl esters and hydroxyalkyl esters thereof with up to 5 carbon atoms. Particularly suitable in this case are hydroxyethyl acrylate and hydroxypropyl acrylate and hydroxyethyl methacrylate and hydroxypropyl methacrylate. Also possible are vinyl acetate, N-vinylpyrrolidone, N-vinylcaprolactam, styrene and methylstyrene.
• the present invention relates to a formulation that contains as additional further component f) a calcium-silicate-hydrate (C-S-H) containing composition.
• C-S-H calcium-silicate-hydrate
• admixtures for building material mixtures comprising hydraulic binders typically also contain hardening accelerators which shorten the setting time of the hydraulic binder.
• hardening accelerators which shorten the setting time of the hydraulic binder.
• C-S-H calcium silicate hydrate
• commercially available C-S-H or corresponding C-S-H dispersions may be regarded only as hardening accelerators which have little effect.
• the C-S-H containing composition is prepareble by reaction of a water-soluble calcium containing compound with a water-soluble silicate containing compound, the reaction of the water-soluble calcium containing compound with the water-soluble silicate containing compound being carried out in the presence of an aqueous solution preferably containing a water-soluble copolymer that preferably is a dispersant for hydraulic binders and selected from at least a representative of component a) and/or b).
• water-soluble calcium compounds and water-soluble silicate compounds are also suitable in each case as water-soluble calcium compounds and water-soluble silicate compounds, although readily water-soluble compounds (which dissolve completely or virtually completely in water) are preferred in each case.
• a reactivity sufficient for the reaction is present in an aqueous environment with the corresponding reactant (either water-soluble calcium compound or water-soluble silicate compound). It is probably to be assumed that the reaction takes place in aqueous solution but a water-insoluble inorganic compound (C-S-H) is usually present as a reaction product.
• comb polymers are to be understood as meaning those polymers which have relatively long side chains (having a molecular weight of in each case at least 200 g/mol, particularly preferably at least 400 g/mol) on a linear main chain at more or less regular intervals.
• the lengths of these side chains are frequently approximately equal but may also differ greatly from one another (for example when polyether macromonomers having side chains of different lengths are incorporated in the form of polymerized units).
• component f) acts as accelerator and in a preferred embodiment contains an inorganic and an organic component.
• the inorganic component may be regarded as modified, finely disperse calcium silicate hydrate (C-S-H) which may contain foreign ions, such as magnesium and aluminium.
• C-S-H can be prepared in the presence of the comb polymer plasticizer (organic component).
• a suspension containing the C-S-H in finely disperse form is obtained, which suspension firstly acts as a plasticizer and secondly effectively accelerates the hardening process of hydraulic binders.
• the inorganic component can in most cases be described with regard to its composition (not with regard to particle size, specific surface area, etc) by the following empirical formula: a CaO, SiO 2 , b Al 2 O 3 , c H 2 O, d X, e W
• the C-S-H shows a calcium/silicium (Ca/Si)-molar ratio of 0.5 to 2.0, preferable 0.7 to 1.8, more preferable 1.6 to 1.7.
• the average particle size of C-S-H is smaller than 10 ⁇ m, preferable smaller than 1 ⁇ m, more preferable smaller than 0.2 ⁇ m, measured by light scattering with the equipment Master Sizer 2000 from the Malvern Company.
• the average particle size of C-S-H is greater 0.01 ⁇ m, preferable 0.1 ⁇ m to 1.0 ⁇ m, more preferable 0.2 ⁇ m to 0.5 ⁇ m.
• the dispersant that is used for this method of preparation can be identical to the representatives of the dispersing component a) and/or b) of the formulation.
• the dispersing agent in this method of preparation is necessary for achieving a small particle size distribution of the C-S-H compound.
• C-S-H containing composition is preperable by reaction of a calcium oxide, a calcium carbonate and/or a calcium hydroxide with a silicium dioxide during milling, the reaction being carried out in the presence of an aqueous solution that preferably contains a water-soluble copolymer that preferably is a dispersant for hydraulic binders and selected from at least a representative of component a) and/or b).
• the water-soluble calcium compound is mixed in a first step, with the aqueous solution which contains a water-soluble comb polymer suitable as a plasticizer for hydraulic binders, so that a mixture preferably present as a solution is obtained, to which the water-soluble silicate compound is added in a subsequent second step.
• the aqueous solution may also contain one or more further solvents in addition to water.
• the aqueous solution containing the dispersant and preferably one that is selected from component a) and/or b) furthermore has the water-soluble calcium compound and the water-soluble silicate compound as components dissolved in it.
• the aqueous solution also contains, in addition to silicate and calcium ions, further dissolved ions which are preferably provided in the form of dissolved aluminium chloride and/or dissolved magnesium chloride.
• the water-soluble dispersant can be a comb polymer and be present as a copolymer which contains, on the back bone, side chains having ether functions and acid functions.
• the water-soluble comb polymer is present as a copolymer which is produced by free radical polymerization in the presence of acid monomer and polyether macromonomer, so that altogether at least 45 mol %, preferably at least 80 mol %, of all structural units of the copolymer are produced by incorporation of acid monomer and polyether macromonomer in the form of polymerized units.
• Acid monomer is to be understood as meaning monomers which are capable of free radical copolymerization, have at least one carbon double bond, contain at least one acid function and react as an acid in an aqueous medium.
• acid monomer is also to be understood as meaning monomers which are capable of free radical copolymerization, have at least one carbon double bond, form at least one acid function in an aqueous medium as a result of a hydrolysis reaction and react as an acid in an aqueous medium (example: maleic anhydride).
• polyether macromonomers are compounds which are capable of free radical copolymerization, have at least one carbon double bond, and have at least two ether oxygen atoms, with the proviso that the polyether macromonomer structural units present in the copolymer have side chains which contain at least two ether oxygen atoms.
• the water-soluble calcium compound is present as calcium chloride, calcium nitrate, calcium formate, calcium acetate, calcium bicarbonate, calcium bromide, calcium carbonate, calcium citrate, calcium chlorate, calcium fluoride, calcium gluconate, calcium hydroxide, calcium hypochloride, calcium iodate, calcium iodide, calcium lactate, calcium nitrite, calcium oxalate, calcium phosphate, calcium propionate, calcium silicate, calcium stearate, calcium sulphate, calcium sulphate hemihydrate, calcium sulphate dihydrate, calcium sulphide, calcium tartrate and/or calcium aluminate, tricalcium silicate and/or dicalcium silicate.
• the water-soluble calcium compound is preferably present as calcium chloride, calcium nitrate and/or calcium formate.
• the water-soluble silicate compound is present as sodium silicate, potassium silicate, waterglass, aluminium silicate, tricalcium silicate, dicalcium silicate, calcium silicate, silicic acid, sodium metasilicate and/or potassium metasilicate.
• the water-soluble silicate compound is preferably present as sodium metasilicate, potassium metasilicate and/or waterglass.
• a calcium silicate (provided that it is soluble) may be used both as a silicate source and as a calcium source. In many cases, however, this is not preferred. As a rule, species of different types are used as the water-soluble silicate compound and as the water-soluble calcium compound.
• the formulation is a liquid or a powder and preferably a redispersant powder.
• the powder form of the formulation can be achieved by any method known to a skilled person. Preferred is the spray drying method that is also suitable for getting the formulation of the invention as redispersant powder.
• the use of the formulation for controlling the flowability of aqueous suspensions used in construction chemistry and in particular in aqueous suspensions containing hydraulic and/or latent hydraulic binders is of main interest.
• the formulation is used in particular as composition with dispersing properties.
• these compositions contain, as a hydraulic binder at least one representative selected from the group consisting of cements and calcium sulphate-based compounds, in particular calcium sulphate hemihydrate, anhydrite or gypsum.
• the aqueous suspension according to the present invention preferably is based on a dry mortar composition or a flooring composition.
• the flooring composition contains calcium sulphate or cement or mixtures thereof, and preferably is a self-leveling flooring composition.
• the formulation according to the present invention is to be used in amounts of 0.001 to 8.0% by weight, in particular 0.005 to 5.0% by weight, preferably 0.01 to 2.0% by weight and particularly preferably 0.05 to 1.0% by weight, based in each case on the total composition of the suspension.
• the present invention comprises the option that the formulation is used together with other admixtures or compositions, preferably with flowability controlling and/or dispersing properties, and more preferably together with at least one dispersant of the type of component a) and/or the polymerisation product b) of the formulation.
• component a) and component b) can be used as formulation according to the present invention and additionally that this formulation can be used together with other compounds, additives, admixtures or compositions.
• components a) and b) can be used as substantial constituents of the formulation and additionally as single compounds together with such formulation.
• This kind of use can be practiced stepwise, that means that either the formulation or the additional dispersants are added to the hydraulic binder containing composition in the first step of use and that additional amounts of the formulation its components are added in up following process steps.
• a reactor equipped with a stirrer and a heating mantle is filled with 600 parts of poly(ethyleneoxide) monophenylether (average molecular weight 5000 g/mol), 47.2 parts of concentrated methane sulfonic acid, 12 parts of water, 110 parts of ⁇ -phenyl- ⁇ -hydroxypoly(oxy-1,2-ethanediyl) phosphate (average molecular weight 368 g/mol) and 14.7 parts of paraformaldehyde.
• This reaction mixture is stirred at 115°C for 3h. After cooling, 830 parts of water are added the reaction mixture is neutralized with 50% sodium hydroxide solution to a pH value of 6.5 to 7.
• the resin is a light yellow colored, clear and aqueous polymer solution with a solid concentration of 40 % by weight.
• the amounts of the materials shown in Table 2 are in percent by weight of the solution.
• a reactor equipped with a stirrer and a heating mantle is filled with 26 parts of polyphosphoric acid and heated to 90°C. Within 15 min 44.2 parts of 2-phenoxyethanol are charged into the reactor. After 1h, 400 parts of poly(ethyleneoxide) monophenylether (average molecular weight 5000 g/mol), 31.4 parts of concentrated methane sulfonic acid, 20 parts of water and 12.6 parts of paraformaldehyde are added. This reaction mixture is stirred at 105 °C for 6h. After cooling, 550 parts of water are added and the reaction mixture is neutralized with 50% sodium hydroxide solution to a pH value of 6.5 to 7.
• the resin is a light brown colored, clear and aqueous polymer solution with a solid concentration of 40 % by weight.
• the amounts of the materials shown in Table 2 are in percent by weight of the solution.
• a reactor equipped with a stirrer and a heating mantle is filled with 51.6 parts of polyphosphoric acid and heated to 90°C. Within 15 min 90 parts of 2-phenoxyethanol are charged into the reactor. After 1 h, 322 parts of poly(ethyleneoxide) monophenylether (average molecular weight 5000 g/mol), 300 parts of poly(ethyleneoxide) monophenylether (average molecular weight 2000 g/mol), 42.1 parts of concentrated methane sulfonic acid, 16.8 parts of water and 28.5 parts of paraformaldehyde are added. This reaction mixture is stirred at 105 °C for 6h.
• the reaction mixture is neutralized with 50% sodium hydroxide solution to a pH value of 6.5 to 7.
• the resin is a light brown colored, clear and aqueous polymer solution with a solid concentration of 40 % by weight.
• the amounts of the materials shown in Table 2 are in percent by weight of the solution.
• the examples E1 till E20 were prepared by mixing the polycondensate components b) with equivalent amounts (wt. %) of the dispersants a).
• Melflux PCE 239 L 35% N.D., Melflux 2500 L 45% N.D., Melflux 2453 L 44% N.D., VP2661/493 L 40% N.D., Melflux 2424 L 50% N.D., Melflux AP 120 L 40%, and Sokalan DS5009 X are a polycarboxylate ether dispersant available from BASF Construction Polymers GmbH, Germany.
• Melcrete 500 L is a naphthalene sulfonate dispersant (BNS) available from BASF Construction Polymers GmbH.
• Melment L 15 G is a melamine sulphonate-formaldehyde condensate (MFS) available from BASF Construction Polymers GmbH.
• the non-ionic polymers N1 and N2 are able to maintain the fluidity of a cement composition and are synthesized according to the still unpublished application US Serial No. 12/477637 .
• antifoaming agent A1 has been a polypropyleneglycol commercially available as Pluriol® P2000 and, antifoaming agent A2 an alkoxylated alcohol commercially available as Degressal® SD23 and antifoaming agent A3 a carboxylic ester commercially available as Degressal® SD30 all from BASF SE (Ludwigshafen, Germany).
• Surfactant S1 was an ethoxylated oxo-alcohol commercially available as Lutensol® TO6 from BASF SE (Ludwigshafen, Germany).
• Surfactant S2 (as component a) is a styrene/maleic acid copolymer which was synthesized according to EP 0306449 A2 .
• Table2 Solution (E: Invention; C: Comparison) Dispersant according to example Antifoaming agent (wt.-%) Surfactant (wt.-%) Stability over 3 months at RT A1 A2 A3
• S1 S2 E21 E1 0.4 0.6 + E22 1.1 0.2 0.3 + E23 1.1 0.4 0.6 + E24 E2 0.2 0.3 + E25 1.2 0.2 0.3 + E26 1.2 0.4 0.8 + E27 1.2 0.2 0.3 + E28 1.1 0.2 0.3 + E29 1.3 0.2 0.3 + E30 E1 0.2 0.3 + E31 E2 0.2 0.3 + C5 1.1 0.4 -)* C6 1.2 0.4 -)* C7 1.1 none none none none none none none none none none none none none n.a. C8 1.2 none
• the viscosities of the dispersants solutions were measured with a capillary viscometer at 25 °C.
• the solutions were prepared by mixing a 25 Wt. % BNS solution with 25 Wt. % solutions of the dispersants as indicated in Table 1 and 3.
• Table 3 Formulation or dispersant Dispersant : BNS ratio Viscosity in mPas C1 - 59.1 C4 1 : 1 529.4 C7 - 28.0 E3 1 : 1 137.1 C8 - 32.9 E4 1 : 1 188.8 C9 - 24.5 E5 1 : 1 83.2
• the viscosity of the admixture E3, E4 and E5 is only slightly higher compared to the viscosity of the pure condensates C7, C8 and C9. Whereas the admixtures E3, E4 and E5 keep their low viscosity over time, the mixture of BNS and the polycarboxylate ether starts to form a non pourable gel. Unlike C4, the admixture E3, E4 and E5 are usable as dispersant agents for hydraulic binders (see below for application tests).
• Alpha hemi hydrate 300 g Sand (0 - 0.2 mm) 350 g Lime stone filler 150 g Citric acid 0.10 g Starvis 3003 F 0.32 g Water 174.6 g Admixture (Superplasticizer) 0.15 %-bws ( by weight of solids)
• the admixtures according to the invention show an excellent antifoaming property.
• the surface of thin layer levelling was found to be free of defects and craters compared to example C8.
• the required amount of liquid admixture was weighted into the mixing cup and water was added to reach the water to stucco ratios given in Table 4.
• the stucco (400 g from various sources) together with the accelerator is sifted into water within 15 sec and afterwards mixed with a Hobart® mixer for 15 sec at high speed (285 rpm). After 60 sec the flow value was measured with a cylinder (height: 10 cm, diameter: 5 cm). The set time was determined by means of the so-called knife cut test.
• the admixture E26 according to the invention show excellent dispersant abilities in comparison to the polycondensate dispersant C8.
• Admixture E31 which contains the polycondensate C8 and the polycarboxylate ether C2, displays a lower amount of accelerator usage as the pure polycarboxylate ether C2.
• the admixtures E7-1 and E7-2 according to the invention display excellent dispersant abilities in FGD stucco and in comparison to the polycarboxylate ether dispersant C3 a significant reduced accelerator demand.
• Admixtures E8-1 and E8-2 show higher flow values than the pure polycondensate C8.
• the admixture according to the invention E26 and E13 possesses fluidity in the natural stucco B.
• the comparison admixture C3 is not fluid whereas C2 needs a significant higher water to stucco ratio to reach the same flow value.
• the admixtures according to the invention display excellent dispersant abilities in the natural stucco C and in comparison to the polycarboxylate ether dispersant C3 reduced accelerator demands.
• the admixtures E26 and E15 have a similar low accelerator demand but a higher fluidity as the polycondensate C8.
• 600 g of cement powder is homogenized in a RILEM-Mixer.
• the required amount of water to reach the water to cement ratios given in Table 9 is added and mixed in for 30 sec at 140 rpm (level I).
• the sand is added during agitation via a funnel and mixed in for 30 sec at 140 rpm (level I).
• the brims of the bowl will be cleaned and the required amount of liquid admixture is added after a mixing break of 1.5 min.
• the mixing is continued for 60 sec at 285 rpm (level II) and afterwards the flow value (spread value) is determined with a Hägermann cylinder according to DIN EN 1015-3.
• the mortar is based on a Karlstadt CEM I 42.5 R and has a sand to cement ratio of 2.2.
• the sand consists of a mixture of 30% quartz sand and 70% standardized sand.
• Table 9 Example Dosage [% solid on cement] w/c ratio Spread value @ 0 min [cm] 15 min 30 min 60 min 90 min blank - 0.545 24.6 23.5 23.5 23 C7 0.19 0.42 24.7 24.1 22.2 21.5 E16 0.27 0.42 25 23.4 22.2 20.5 BNS 0.50 0.42 24.9 23.6 22.5 21.2 E17 0.20 0.43 24.3 23.4 22.9 E18 0.20 0.40 25.0 25.5 24.9 24.5 E19 0.20 0.41 24.4 24.0 23.4 E13 0.23 0.43 23.5 23.8 25.4 25.2 24.4 E20 0.24 0.43 24.0 24.1 24.3 23.7 23.4
• the admixture E16 that contains the low-cost dispersant BNS, displays similar fluidity as the condensate C7 at a much lower dosage level than BNS.
• the admixtures E18 and in particular E13 and E20 keep the fluidity of the cementious binder composition for more than 90 min.

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• 2010
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